Abstract: A semiconductor transistor structure with reduced contact resistance includes a substrate, a channel layer on the substrate, a barrier layer on the channel layer, a two-dimensional electron gas (2DEG) layer at an interface between the barrier layer and the channel layer, and a recess in a contact region. The recess penetrates through the barrier layer and extends into the channel layer. An Ohmic contact metal is disposed in the recess. The Ohmic contact metal is in direct contact with a vertical side surface of the barrier layer in the recess and in direct contact with an inclined side surface of the 2DEG layer and the channel layer in the recess.

Abstract: The semiconductor device of the present invention includes a first conductivity type semiconductor layer made of a wide bandgap semiconductor and a Schottky electrode formed to come into contact with a surface of the semiconductor layer, and has a threshold voltage Vth of 0.3 V to 0.7 V and a leakage current Jr of 1×10?9 A/cm2 to 1×10?4 A/cm2 in a rated voltage VR.

Abstract: Gate metallization structures and methods for semiconductor devices are disclosed, wherein a refractory metal barrier is implemented to provide performance improvements. Transistor devices are disclosed having a compound semiconductor substrate and an electron-beam evaporated gate structure including a layer of tantalum nitride (TaNx), a layer of titanium (Ti) and a layer of gold (Au).

Abstract: A wafer processing method including a fixing step of providing a wafer on a protective member so that a device area of the wafer faces an unevenness absorbing member provided in a recess of the protective member and providing an adhesive outside the device area to thereby fix the protective member and the wafer, a grinding step of holding the protective member on a holding table in the condition where the back side of the wafer is exposed and next grinding the back side of the wafer by using a grinding unit to thereby reduce the thickness of the wafer to a predetermined thickness, and a removing step of removing the protective member from the wafer. The adhesive is locally provided outside of the device area, so that the protective member can be easily removed from the wafer without leaving the adhesive on the front side of each device.

Abstract: A method for manufacturing a rectifier with a vertical MOS structure is provided. A first multi-trench structure and a first mask layer are formed at a first side of the semiconductor substrate. A second multi-trench structure is formed in the second side of the semiconductor substrate. A gate oxide layer, a polysilicon structure and a metal sputtering layer are sequentially formed on the second multi-trench structure. The rectifier further includes a wet oxide layer and a plurality of doped regions. The wet oxide layer is formed on a surface of the first multi-trench structure and in the semiconductor substrate. The doping regions are formed on a region between the semiconductor substrate and the second multi-trench structure, and located beside the mask layer. The metal sputtering layer is formed on the first mask layer corresponding to the first multi-trench structure.

Abstract: A method of forming strained source and drain regions in a P-type FinFET structure is disclose. The method comprises depositing an isolation layer on the FinFET structure; applying a lithography and etching process to expose the isolation layer in two areas on opposite sides of the gate over the source/drain region of the FinFET, and etching through the exposed isolation layer to expose the semiconductive material of the source/drain region in the two areas; forming a recess in each of the source/drain region from the exposed semiconductive material; selectively epitaxially growing another semiconductive material in the recesses to increase the source/drain strain; and removing the rest of the isolation layer.

Abstract: The present invention aims at providing a semiconductor device having a conductive film formed on a semiconducting substrate so that heating of the substrate and contamination by impurities can be suppressed and Schottky resistance can be reduced, and at providing a method of manufacturing the same. The metal film formation method used in manufacturing the semiconductor device according to an embodiment of the present invention includes the steps of: irradiating one surface of the substrate with a femtosecond laser having energy in the vicinity of the processing threshold value to form a nano-periodic structure in the form of minute irregularities; and forming a metal film on the nano-periodic structure of the substrate. It is thereby possible to reduce the Schottky resistance at the interface between the substrate and the metal film and obtain an ohmic contact while suppressing heating of the substrate and contamination by impurities.

Abstract: A semiconductor structure includes a GaN substrate having a first surface and a second surface opposing the first surface. The GaN substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a first GaN epitaxial layer of the first conductivity type coupled to the second surface of the GaN substrate and a second GaN epitaxial layer of a second conductivity type coupled to the first GaN epitaxial layer. The second GaN epitaxial layer includes an active device region, a first junction termination region characterized by an implantation region having a first implantation profile, and a second junction termination region characterized by an implantation region having a second implantation profile.

Abstract: A Schottky barrier diode and fabricating method thereof are disclosed. A semiconductor substrate may have a first surface and a second surface positioned oppositely to be provided. Several trenches are formed on the first surface. Each trench has a sidewall with a first depth and a first bottom surface. An insulating material is formed on the first surface of the semiconductor substrate and on the sidewall and the first bottom surface of each trench, wherein the insulating material has a first thickness on the sidewall. The insulating material on the sidewall is patterned to define a second bottom surface having a second depth smaller than the first depth, and the removed portion of the insulating material on the sidewall has a second thickness smaller than the first thickness. Afterward, a contact metal layer is at least formed on the first surface between adjacent trenches.

Abstract: A method for producing a protective structure may include: providing a semiconductor base substrate with a doping of a first conductivity type; producing a first epitaxial layer on the substrate; implanting a dopant of a second conductivity type in a delimited implantation region of the first epitaxial layer; applying a second epitaxial layer with a doping of the second conductivity type on the first epitaxial layer; forming an insulation zone in the second epitaxial layer, such that the second epitaxial layer is subdivided into first and second regions; producing a first dopant zone with a doping of the first conductivity type in the first region above the implantation region; producing a second dopant zone with a doping of the second conductivity type in the second region; outdiffusing the dopant from the implantation region to form a buried layer at the junction between the first epitaxial layer and the first region.

Abstract: A semiconductor switch device and a method of manufacturing the semiconductor switch device are provided. The semiconductor switch device includes semiconductor elements on a single semiconductor substrate. At least one of the semiconductor elements constitutes a switch circuit and at least one other of the semiconductor elements constitutes a logic (connection) circuit. Each semiconductor element includes a recess, a gate electrode in the recess, a drain electrode, and a source electrode. In one representative aspect, the gate electrode in the switch circuit can have a rectangular external shape in section, and the gate electrode in the connection circuit has a shape in section other than rectangular.

Abstract: A trench Schottky diode and its manufacturing method are provided. The trench Schottky diode includes a semiconductor substrate having therein a plurality of trenches, a gate oxide layer, a polysilicon structure, a guard ring and an electrode. At first, the trenches are formed in the semiconductor substrate by an etching step. Then, the gate oxide layer and the polysilicon structure are formed in the trenches and protrude above a surface of the semiconductor substrate. The guard ring is formed to cover a portion of the resultant structure. At last, the electrode is formed above the guard ring and the other portion not covered by the guard ring. The protruding gate oxide layer and the protruding polysilicon structure can avoid cracks occurring in the trench structure.

Abstract: A transistor having at least one passivated Schottky barrier to a channel includes an insulated gate structure on a p-type substrate in which the channel is located beneath the insulated gate structure. The channel and the insulated gate structure define a first and second undercut void regions that extend underneath the insulated gate structure toward the channel from a first and a second side of the insulated gate structure, respectively. A passivation layer is included on at least one exposed sidewall surface of the channel, and metal source and drain terminals are located on respective first and second sides of the channel, including on the passivation layer and within the undercut void regions beneath the insulated gate structure. At least one of the metal source and drain terminals comprises a metal that has a work function near a valence band of the p-type substrate.

Abstract: A diode is described with a III-N material structure, an electrically conductive channel in the III-N material structure, two terminals, wherein a first terminal is an anode adjacent to the III-N material structure and a second terminal is a cathode in ohmic contact with the electrically conductive channel, and a dielectric layer over at least a portion of the anode. The anode comprises a first metal layer adjacent to the III-N material structure, a second metal layer, and an intermediary electrically conductive structure between the first metal layer and the second metal layer. The intermediary electrically conductive structure reduces a shift in an on-voltage or reduces a shift in reverse bias current of the diode resulting from the inclusion of the dielectric layer. The diode can be a high voltage device and can have low reverse bias currents.

Abstract: Some embodiments include methods of forming diodes in which a first electrode is formed to have a pedestal extending upwardly from a base. At least one layer is deposited along an undulating topography that extends across the pedestal and base, and a second electrode is formed over the least one layer. The first electrode, at least one layer, and second electrode together form a structure that conducts current between the first and second electrodes when voltage of one polarity is applied to the structure, and that inhibits current flow between the first and second electrodes when voltage having a polarity opposite to said one polarity is applied to the structure. Some embodiments include diodes having a first electrode that contains two or more projections extending upwardly from a base, having at least one layer over the first electrode, and having a second electrode over the at least one layer.

Abstract: A method for manufacturing a rectifier with a vertical MOS structure is provided. A first trench structure and a first mask layer are formed at a first side of the semiconductor substrate. A second trench structure is formed in the second side of the semiconductor substrate. A gate oxide layer, a polysilicon structure and a metal sputtering layer are sequentially formed on the second trench structure. The rectifier further includes a wet oxide layer and a plurality of doped regions. The wet oxide layer is formed on a surface of the first multi-trench structure and in the semiconductor substrate. The doping regions are formed on a region between the semiconductor substrate and the second trench structure, and located beside the mask layer. The metal sputtering layer is formed on the first mask layer corresponding to the first trench structure.

Abstract: A semiconductor system is described, which includes a trench junction barrier Schottky diode having an integrated p-n type diode as a clamping element, which is suitable for use in motor vehicle generator system, in particular as a Zener diode having a breakdown voltage of approximately 20V. In this case, the TJBS is a combination of a Schottky diode and a p-n type diode. Where the breakdown voltages are concerned, the breakdown voltage of the p-n type diode is lower than the breakdown voltage of Schottky diode. The semiconductor system may therefore be operated using high currents at breakdown.

Abstract: An integrated structure combines field effect transistors and a Schottky diode. Trenches formed into a substrate composition extend along a depth of the substrate composition forming mesas therebetween. Each trench is filled with conductive material separated from the trench walls by dielectric material forming a gate region. Two first conductivity type body regions inside each mesa form wells partly into the depth of the substrate composition. An exposed portion of the substrate composition separates the body regions. Second conductivity type source regions inside each body region are adjacent to and on opposite sides of each well. Schottky barrier metal inside each well forms Schottky junctions at interfaces with exposed vertical sidewalls of the exposed portion of the substrate composition separating the body regions.

Abstract: A III-nitride semiconductor device includes an active region for supporting current flow during forward-biased operation of the III-nitride semiconductor device. The active region includes a first III-nitride epitaxial material having a first conductivity type, and a second III-nitride epitaxial material having a second conductivity type. The III-nitride semiconductor device further includes an edge-termination region physically adjacent to the active region and including an implanted region comprising a portion of the first III-nitride epitaxial material. The implanted region of the first III-nitride epitaxial material has a reduced electrical conductivity in relation to portions of the first III-nitride epitaxial material adjacent to the implanted region.

Abstract: A multi-trench termination structure for semiconductor device is disclosed, where the semiconductor device includes a semiconductor substrate and an active structure region. The multi-trench termination structure includes multiple trenches defined on an exposed face of the semiconductor substrate, a first mask layer formed on a partial exposed surface of the semiconductor substrate and corresponding to a termination structure region of the semiconductor device, a gate insulation layer formed in the trenches, a conductive layer formed on the gate insulation layer and protruding out of the exposed surface of the semiconductor substrate, and a metal layer formed over the first mask layer and conductive layer on the termination structure region of the semiconductor device.

Abstract: A semiconductor structure includes a GaN substrate having a first surface and a second surface opposing the first surface. The GaN substrate is characterized by a first conductivity type and a first dopant concentration. The semiconductor structure also includes a first GaN epitaxial layer of the first conductivity type coupled to the second surface of the GaN substrate and a second GaN epitaxial layer of a second conductivity type coupled to the first GaN epitaxial layer. The second GaN epitaxial layer includes an active device region, a first junction termination region characterized by an implantation region having a first implantation profile, and a second junction termination region characterized by an implantation region having a second implantation profile.

Abstract: A method for manufacturing a semiconductor structure is disclosed. The method comprises following steps. A substrate is provided. A sacrificial layer is formed on the substrate. The sacrificial layer is patterned to develop a first opening and a second opening. The first opening corresponds to an exposed portion of the substrate and the second opening corresponds to an unexposed portion of the substrate. A heat procedure is performed. A target material is formed on the exposed portion of the substrate and a rest part of the sacrificial layer. The rest part of the sacrificial layer and parts of the target material on the rest part of the sacrificial layer are removed. A predetermined patterned target material is obtained.

Abstract: A multi-trench termination structure for semiconductor device is disclosed, where the semiconductor device includes a semiconductor substrate and an active structure region. The multi-trench termination structure includes multiple trenches defined on an exposed face of the semiconductor substrate, a first mask layer formed on a partial exposed surface of the semiconductor substrate and corresponding to a termination structure region of the semiconductor device, a gate insulation layer formed in the trenches, a conductive layer formed on the gate insulation layer and protruding out of the exposed surface of the semiconductor substrate, and a metal layer formed over the first mask layer and conductive layer on the termination structure region of the semiconductor device.

Abstract: A method for manufacturing a rectifier with a vertical MOS structure is provided. A first trench structure and a first mask layer are formed at a first side of the semiconductor substrate. A second trench structure is formed in the second side of the semiconductor substrate. A gate oxide layer, a polysilicon structure and a metal sputtering layer are sequentially formed on the second trench structure. The rectifier further includes a wet oxide layer and a plurality of doped regions. The wet oxide layer is formed on a surface of the first multi-trench structure and in the semiconductor substrate. The doping regions are formed on a region between the semiconductor substrate and the second trench structure, and located beside the mask layer. The metal sputtering layer is formed on the first mask layer corresponding to the first trench structure.

Abstract: In an MIS-type GaN-FET, a base layer made of a conductive nitride including no oxygen, here, TaN, is provided on a surface layer as a nitride semiconductor layer to cover at least an area of a lower face of a gate insulation film made of Ta2O5 under a gate electrode.

Abstract: A manufacturing method for a semiconductor device having a metal gate includes providing a substrate having at least a first semiconductor device formed thereon, forming a first gate trench in the first semiconductor device, forming a first work function metal layer in the first gate trench, and performing a decoupled plasma oxidation to the first work function metal layer.

Abstract: A device and method for forming a semiconductor device include growing a raised semiconductor region on a channel layer adjacent to a gate structure. A space is formed between the raised semiconductor region and the gate structure. A metal layer is deposited on at least the raised semiconductor region. The raised semiconductor region is silicided to form a silicide into the channel layer which extends deeper into the channel layer at a position corresponding to the space.

Abstract: A method of manufacturing of a semiconductor device (101) includes: a fine pattern forming step of forming p-type impurity regions (3, 4) and surface ohmic contact electrodes (5) using a stepper, after forming an N-type epitaxial layer (2) on a SiC single-crystal substrate (1); a protective film planarizing step of forming a protective film so as to cover the surface ohmic contact electrodes (5) and performing planarization of the protective film; a substrate thinning step of thinning the SiC single-crystal substrate (1); a backside ohmic contact electrode forming step of forming a backside ohmic contact electrode (7) on the SiC single-crystal substrate (1); a surface Schottky contact electrode forming step of forming a Schottky metal portion (8) connected to the p-type impurity regions (3, 4) and the surface ohmic contact electrodes (5); and a step of forming a surface pad electrode (9) that covers the Schottky metal portion (8).

Abstract: A Schottky diode with a small footprint and a high-current carrying ability is fabricated by forming an opening that extends into an n-type semiconductor material. The opening is then lined with a metallic material such as platinum. The metallic material is then heated to form a salicide region where the metallic material touches the n-type semiconductor material.

Abstract: A Schottky photodiode may include a monocrystalline semiconductor substrate having a front surface, a rear surface, and a first dopant concentration and configured to define a cathode of the Schottky photodiode, a doped epitaxial layer over the front surface of the monocrystalline semiconductor substrate having a second dopant concentration less than the first dopant concentration, and parallel spaced apart trenches in the doped epitaxial layer and having of a depth less than a depth of the doped epitaxial layer.

Abstract: A semiconductor device includes a trench MOS barrier Schottky diode having an integrated PN diode and a method is for manufacturing same.

Abstract: A Schottky junction type semiconductor device in which the opening width of a trench can be decreased without deteriorating the withstanding voltage. The cross sectional shape of a trench has a shape of a sub-trench in which the central portion is higher and the periphery is lower at the bottom of the trench, and a p type impurity is introduced vertically to the surface of the drift layer thereby forming a p+ SiC region, which is formed in contact to the inner wall of the trench having the sub-trench disposed therein, such that the junction position is formed more deeply in the periphery of the bottom of the trench than the junction position in the central portion of the bottom of the trench.

Abstract: An integrated structure combines field effect transistors and a Schottky diode. Trenches formed into a substrate composition extend along a depth of the substrate composition forming mesas therebetween. Each trench is filled with conductive material separated from the trench walls by dielectric material forming a gate region. Two first conductivity type body regions inside each mesa form wells partly into the depth of the substrate composition. An exposed portion of the substrate composition separates the body regions. Second conductivity type source regions inside each body region are adjacent to and on opposite sides of each well. Schottky barrier metal inside each well forms Schottky junctions at interfaces with exposed vertical sidewalls of the exposed portion of the substrate composition separating the body regions.

Abstract: The present invention provides a semiconductor device and a method for manufacturing the same. The method includes: providing a substrate; forming a gate stack on the substrate; forming an inter layer dielectric (ILD) to cover the device; etching the ILD at both sides of the gate stack and the substrate below the ILD, so as to form a groove of source and drain regions respectively; depositing a metal diffusion barrier layer in the groove; and filling the groove with a metal to form the source and drain regions. The semiconductor device includes: a substrate; a gate stack on the substrate; an inter layer dielectric (ILD) covering the device; a groove of source and drain regions formed in the ILD at both sides of the gate stack and the substrate below the ILD; and a metal diffusion barrier layer and a metal filler formed in the groove.

Abstract: A trench Schottky diode and its manufacturing method are provided. The trench Schottky diode includes a semiconductor substrate having therein a plurality of trenches, a gate oxide layer, a polysilicon structure, a guard ring and an electrode. At first, the trenches are formed in the semiconductor substrate by an etching step. Then, the gate oxide layer and the polysilicon structure are formed in the trenches and protrude above a surface of the semiconductor substrate. The guard ring is formed to cover a portion of the resultant structure. At last, the electrode is formed above the guard ring and the other portion not covered by the guard ring. The protruding gate oxide layer and the protruding polysilicon structure can avoid cracks occurring in the trench structure.

Abstract: A transistor includes a semiconductor channel disposed nearby a gate and in an electrical path between a source and a drain, wherein the channel and at least one of the source or the drain are separated by an interface layer so as to form a channel-interface layer-source/drain junction in which a Fermi level of the semiconductor channel is depinned in a region near the junction and the junction has a specific contact resistance of less than approximately 1000 ?-?m2. The interface layer may include a passivating material such as a nitride, a fluoride, an oxide, an oxynitride, a hydride and/or an arsenide of the semiconductor of the channel. In some cases, the interface layer consists essentially of a monolayer configured to depin the Fermi level of the semiconductor of the channel, or an amount of passivation material sufficient to terminate all or a sufficient number of dangling bonds of the semiconductor channel to achieve chemical stability of the surface.

Abstract: This invention discloses a gallium nitride based semiconductor power device disposed in a semiconductor substrate. The power device comprises a termination area disposed at a peripheral area of the semiconductor power device comprises a termination structure having at least a guard ring disposed in a trench filled with doped gallium-based epitaxial layer therein.

Abstract: In a semiconductor film having a heterojunction structure, for example a semiconductor film including a SiGe layer and a Si layer formed on the SiGe layer, impurity concentration is controlled in such a manner that the concentration of impurity in the lower, SiGe layer becomes higher than that in the upper, Si layer by exploiting the fact that there is a difference between the SiGe layer and the Si layer in the diffusion coefficient of the impurity. The impurity contained in the semiconductor film 11 is of the conductivity type opposite to that of the transistor (p-type in the case of an n-type MOS transistor whereas n-type in the case of a p-type MOS transistor). In this way, the mobility in a semiconductor device including a semiconductor film having a heterojunction structure with a compression strain structure is increased, thereby improving the transistor characteristics and reliability of the device.

Abstract: A process for fabricating a semiconductor device. The process includes (a) growing an n-channel layer of gallium arsenide (GaAs) on a buffer layer, (b) growing a barrier layer on the re-channel layer, (c) epitaxially growing a first etch-stop layer on the barrier layer, (d) growing a first contact layer of wide band-gap material on the first etch-stop layer, (e) epitaxially growing a second etch-stop layer on the first contact layer, (f) growing a second contact layer on the second etch-stop layer, where the second contact layer is a highly doped material, and (g) selectively etching portions of the first contact layer, the second etch-stop layer, and the second contact layer to form a gate region.

Abstract: An electronic device includes a drift region, a Schottky contact on a surface of the drift region, and an edge termination structure in the drift region adjacent the Schottky contact. The edge termination structure includes a recessed region that is recessed from the surface of the drift region by a distance d that may be about 0.5 microns.

Abstract: Some embodiments include methods of forming diodes in which a first electrode is formed to have a pedestal extending upwardly from a base. At least one layer is deposited along an undulating topography that extends across the pedestal and base, and a second electrode is formed over the least one layer. The first electrode, at least one layer, and second electrode together form a structure that conducts current between the first and second electrodes when voltage of one polarity is applied to the structure, and that inhibits current flow between the first and second electrodes when voltage having a polarity opposite to said one polarity is applied to the structure. Some embodiments include diodes having a first electrode that contains two or more projections extending upwardly from a base, having at least one layer over the first electrode, and having a second electrode over the at least one layer.

Abstract: A method far farming different active thicknesses on the same silicon layer includes masking the silicon layer and exposing selected regions of the silicon layer. The thickness of the silicon layer at the exposed regions is changed, either by adding silicon or subtracting silicon from the layer at the exposed regions. Once the mask is removed, the silicon layer has regions of different active thicknesses, respectively suitable for use in different types of devices, such as diodes and transistors.

Abstract: A Schottky diode includes a Schottky barrier and a plurality of dopant regions disposed near the Schottky barrier as floating islands to function as PN junctions for preventing a leakage current generated from a reverse voltage. At least a trench opened in a semiconductor substrate with a Schottky barrier material disposed therein constitutes the Schottky barrier. The Schottky barrier material may also be disposed on sidewalls of the trench for constituting the Schottky barrier. The trench may be filled with the Schottky barrier material composed of Ti/TiN or a tungsten metal disposed therein for constituting the Schottky barrier. The trench is opened in a N-type semiconductor substrate and the dopant regions includes P-doped regions disposed under the trench constitute the floating islands. The P-doped floating islands may be formed as vertical arrays under the bottom of the trench.

Abstract: A transistor structure optimizes current along the A-face of a silicon carbide body to form an AMOSFET that minimizes the JFET effect in the drift region during forward conduction in the on-state. The AMOSFET further shows high voltage blocking ability due to the addition of a highly doped well region that protects the gate corner region in a trench-gated device. The AMOSFET uses the A-face conduction along a trench sidewall in addition to a buried channel layer extending across portions of the semiconductor mesas defining the trench. A doped well extends from at least one of the mesas to a depth within the current spreading layer that is greater than the depth of the trench. A current spreading layer extends between the semiconductor mesas beneath the bottom of the trench to reduce junction resistance in the on-state. A buffer layer between the trench and the deep well further provides protection from field crowding at the trench corner.

Abstract: The contact resistance between an Ohmic electrode and an electron transit layer is reduced compared with a case in which the Ohmic electrode is provided to a depth less than the heterointerface. As a result, for an Ohmic electrode provided in a structure comprising an electron transit layer formed of a first semiconductor layer formed on a substrate, an electron supply layer comprising a second semiconductor layer forming a heterojunction with the electron transit layer and having a smaller electron affinity than the first semiconductor layer, and a two-dimensional electron layer induced in the electron transit layer in the vicinity of the heterointerface, the end portion of the Ohmic electrode is positioned in the electron transit layer in penetration into the electron supply layer at a depth equal to or greater than the heterointerface.

Abstract: A method for fabricating a field effect transistor includes: forming an insulating film provided on a semiconductor layer, the insulating film having an opening via which a surface of the semiconductor layer is exposed and including silicon oxide; forming a Schottky electrode on the insulating film and in the opening, the Schottky electrode having an overhang portion and having a first contact layer that is provided in a region contacting the insulating film and contains oxygen, and a second contact layer that is provided on the first contact layer and contains a smaller content of oxygen than that of the first contact layer; and removing the insulating film by a solution including hydrofluoric acid.

Abstract: A semiconductor component is proposed which has a semiconductor body having a first semiconductor zone of the first conduction type, at least one first rectifying junction with respect to the first semiconductor zone, at least one second rectifying junction with respect to the first semiconductor zone, wherein the three rectifying junctions each have a barrier height of different magnitude.

Abstract: A method of forming a buried gate electrode prevents voids from being formed in a silicide layer of the gate electrode. The method begins by forming a trench in a semiconductor substrate, forming a conformal gate oxide layer on the semiconductor in which the trench has been formed, forming a first gate electrode layer on the gate oxide layer, forming a silicon layer on the first gate electrode layer to fill the trench. Then, a portion of the first gate electrode layer is removed to form a recess which exposed a portion of a lateral surface of the silicon layer. A metal layer is then formed on the semiconductor substrate including on the silicon layer. Next, the semiconductor substrate is annealed while the lateral surface of the silicon layer is exposed to form a metal silicide layer on the silicon layer.

Abstract: In an MIS-type GaN-FET, a base layer made of a conductive nitride including no oxygen, here, TaN, is provided on a surface layer as a nitride semiconductor layer to cover at least an area of a lower face of a gate insulation film made of Ta2O5 under a gate electrode.

Abstract: A fabrication process for a trench Schottky diode with differential oxide thickness within the trenches includes forming a first nitride layer on a substrate surface and subsequently forming a plurality of trenches in the substrate including, possibly, a termination trench. Following a sacrificial oxide layer formation and removal, sidewall and bottom surfaces of the trenches are oxidized. A second nitride layer is then applied to the substrate and etched such that the second nitride layer covers the oxide layer on the trench sidewalls but exposes the oxide layer on the trench bottom surfaces. The trench bottom surfaces are then re-oxidized and the remaining second nitride layer then removed from the sidewalls, resulting in an oxide layer of varying thickness being formed on the sidewall and bottom surfaces of each trench. The trenches are then filled with a P type polysilicon, the first nitride layer removed, and a Schottky barrier metal applied to the substrate surface.